Revert 186643 - Caused a 10% regression on SunSpider benchmark

chrome/renderer/extensions/event_bindings.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/extensions/event_bindings.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/basictypes.h"
@@ skipping 54 matching lines @@
 
 // A map of extension IDs to filtered listener counts for that extension.
 base::LazyInstance<std::map<std::string, FilteredEventListenerCounts> >
     g_filtered_listener_counts = LAZY_INSTANCE_INITIALIZER;
 
 base::LazyInstance<EventFilter> g_event_filter = LAZY_INSTANCE_INITIALIZER;
 
 // TODO(koz): Merge this into EventBindings.
 class ExtensionImpl : public ChromeV8Extension {
  public:
-  explicit ExtensionImpl(Dispatcher* dispatcher,
-                         v8::Handle<v8::Context> v8_context)
-      : ChromeV8Extension(dispatcher, v8_context) {
+  explicit ExtensionImpl(Dispatcher* dispatcher)
+      : ChromeV8Extension(dispatcher) {
     RouteStaticFunction("AttachEvent", &AttachEvent);
     RouteStaticFunction("DetachEvent", &DetachEvent);
     RouteStaticFunction("AttachFilteredEvent", &AttachFilteredEvent);
     RouteStaticFunction("DetachFilteredEvent", &DetachFilteredEvent);
     RouteStaticFunction("MatchAgainstEventFilter", &MatchAgainstEventFilter);
   }
 
   virtual ~ExtensionImpl() {}
 
   // Attach an event name to an object.
   static v8::Handle<v8::Value> AttachEvent(const v8::Arguments& args) {
     DCHECK(args.Length() == 1);
     // TODO(erikkay) should enforce that event name is a string in the bindings
     DCHECK(args[0]->IsString() || args[0]->IsUndefined());
 
     if (args[0]->IsString()) {
       ExtensionImpl* self = GetFromArguments<ExtensionImpl>(args);
       std::string event_name = *v8::String::AsciiValue(args[0]->ToString());
       Dispatcher* dispatcher = self->dispatcher();
       const ChromeV8ContextSet& context_set = dispatcher->v8_context_set();
-      ChromeV8Context* context = context_set.GetByV8Context(self->v8_context());
+      ChromeV8Context* context = context_set.GetCurrent();
       CHECK(context);
 
-      if (!dispatcher->CheckContextAccessToExtensionAPI(event_name, context))
+      if (!dispatcher->CheckCurrentContextAccessToExtensionAPI(event_name))
         return v8::Undefined();
 
       std::string extension_id = context->GetExtensionID();
       EventListenerCounts& listener_counts =
           g_listener_counts.Get()[extension_id];
       if (++listener_counts[event_name] == 1) {
         content::RenderThread::Get()->Send(
             new ExtensionHostMsg_AddListener(extension_id, event_name));
       }
 
       // This is called the first time the page has added a listener. Since
       // the background page is the only lazy page, we know this is the first
       // time this listener has been registered.
-      if (IsLazyBackgroundPage(self->GetRenderView(), context->extension())) {
+      if (IsLazyBackgroundPage(context->extension())) {
         content::RenderThread::Get()->Send(
             new ExtensionHostMsg_AddLazyListener(extension_id, event_name));
       }
     }
     return v8::Undefined();
   }
 
   static v8::Handle<v8::Value> DetachEvent(const v8::Arguments& args) {
     DCHECK(args.Length() == 2);
     // TODO(erikkay) should enforce that event name is a string in the bindings
     DCHECK(args[0]->IsString() || args[0]->IsUndefined());
 
     if (args[0]->IsString() && args[1]->IsBoolean()) {
       std::string event_name = *v8::String::AsciiValue(args[0]->ToString());
       bool is_manual = args[1]->BooleanValue();
 
       ExtensionImpl* self = GetFromArguments<ExtensionImpl>(args);
       Dispatcher* dispatcher = self->dispatcher();
       const ChromeV8ContextSet& context_set = dispatcher->v8_context_set();
-      ChromeV8Context* context = context_set.GetByV8Context(self->v8_context());
+      ChromeV8Context* context = context_set.GetCurrent();
       if (!context)
         return v8::Undefined();
 
       std::string extension_id = context->GetExtensionID();
       EventListenerCounts& listener_counts =
           g_listener_counts.Get()[extension_id];
 
       if (--listener_counts[event_name] == 0) {
         content::RenderThread::Get()->Send(
             new ExtensionHostMsg_RemoveListener(extension_id, event_name));
       }
 
       // DetachEvent is called when the last listener for the context is
       // removed. If the context is the background page, and it removes the
       // last listener manually, then we assume that it is no longer interested
       // in being awakened for this event.
-      if (is_manual && IsLazyBackgroundPage(self->GetRenderView(),
-                                            context->extension())) {
+      if (is_manual && IsLazyBackgroundPage(context->extension())) {
         content::RenderThread::Get()->Send(
             new ExtensionHostMsg_RemoveLazyListener(extension_id, event_name));
       }
     }
     return v8::Undefined();
   }
 
   // MatcherID AttachFilteredEvent(string event_name, object filter)
   // event_name - Name of the event to attach.
   // filter - Which instances of the named event are we interested in.
   // returns the id assigned to the listener, which will be returned from calls
   // to MatchAgainstEventFilter where this listener matches.
   static v8::Handle<v8::Value> AttachFilteredEvent(const v8::Arguments& args) {
     DCHECK_EQ(2, args.Length());
     DCHECK(args[0]->IsString());
     DCHECK(args[1]->IsObject());
 
     ExtensionImpl* self = GetFromArguments<ExtensionImpl>(args);
     Dispatcher* dispatcher = self->dispatcher();
     const ChromeV8ContextSet& context_set = dispatcher->v8_context_set();
-    ChromeV8Context* context = context_set.GetByV8Context(self->v8_context());
+    ChromeV8Context* context = context_set.GetCurrent();
     DCHECK(context);
     if (!context)
       return v8::Integer::New(-1);
 
     std::string event_name = *v8::String::AsciiValue(args[0]);
     // This method throws an exception if it returns false.
-    if (!dispatcher->CheckContextAccessToExtensionAPI(event_name, context))
+    if (!dispatcher->CheckCurrentContextAccessToExtensionAPI(event_name))
       return v8::Undefined();
 
     std::string extension_id = context->GetExtensionID();
     if (extension_id.empty())
       return v8::Integer::New(-1);
 
     scoped_ptr<base::DictionaryValue> filter;
     scoped_ptr<content::V8ValueConverter> converter(
         content::V8ValueConverter::create());
 
     base::DictionaryValue* filter_dict = NULL;
-    base::Value* filter_value =
-        converter->FromV8Value(args[1]->ToObject(), context->v8_context());
+    base::Value* filter_value = converter->FromV8Value(args[1]->ToObject(),
+        v8::Context::GetCurrent());
     if (!filter_value)
       return v8::Integer::New(-1);
     if (!filter_value->GetAsDictionary(&filter_dict)) {
       delete filter_value;
       return v8::Integer::New(-1);
     }
 
     filter.reset(filter_dict);
     EventFilter& event_filter = g_event_filter.Get();
     int id = event_filter.AddEventMatcher(event_name, ParseEventMatcher(
         filter.get()));
 
     // Only send IPCs the first time a filter gets added.
     if (AddFilter(event_name, extension_id, filter.get())) {
-      bool lazy = IsLazyBackgroundPage(self->GetRenderView(),
-                                       context->extension());
+      bool lazy = IsLazyBackgroundPage(context->extension());
       content::RenderThread::Get()->Send(
           new ExtensionHostMsg_AddFilteredListener(extension_id, event_name,
                                                    *filter, lazy));
     }
 
     return v8::Integer::New(id);
   }
 
   // Add a filter to |event_name| in |extension_id|, returning true if it
   // was the first filter for that event in that extension.
@@ skipping 28 matching lines @@
   // manual - false if this is part of the extension unload process where all
   //          listeners are automatically detached.
   static v8::Handle<v8::Value> DetachFilteredEvent(const v8::Arguments& args) {
     DCHECK_EQ(2, args.Length());
     DCHECK(args[0]->IsInt32());
     DCHECK(args[1]->IsBoolean());
     bool is_manual = args[1]->BooleanValue();
     ExtensionImpl* self = GetFromArguments<ExtensionImpl>(args);
     Dispatcher* dispatcher = self->dispatcher();
     const ChromeV8ContextSet& context_set = dispatcher->v8_context_set();
-    ChromeV8Context* context = context_set.GetByV8Context(self->v8_context());
+    ChromeV8Context* context = context_set.GetCurrent();
     if (!context)
       return v8::Undefined();
 
     std::string extension_id = context->GetExtensionID();
     if (extension_id.empty())
       return v8::Undefined();
 
     int matcher_id = args[0]->Int32Value();
     EventFilter& event_filter = g_event_filter.Get();
     EventMatcher* event_matcher =
         event_filter.GetEventMatcher(matcher_id);
 
     const std::string& event_name = event_filter.GetEventName(matcher_id);
 
     // Only send IPCs the last time a filter gets removed.
     if (RemoveFilter(event_name, extension_id, event_matcher->value())) {
-      bool lazy = is_manual && IsLazyBackgroundPage(self->GetRenderView(),
-                                                    context->extension());
+      bool lazy = is_manual && IsLazyBackgroundPage(context->extension());
       content::RenderThread::Get()->Send(
           new ExtensionHostMsg_RemoveFilteredListener(extension_id, event_name,
                                                       *event_matcher->value(),
                                                       lazy));
     }
 
     event_filter.RemoveEventMatcher(matcher_id);
 
     return v8::Undefined();
   }
@@ skipping 20 matching lines @@
     EventFilteringInfo info;
     v8::Handle<v8::String> url(v8::String::New("url"));
     if (object->Has(url)) {
       v8::Handle<v8::Value> url_value(object->Get(url));
       info.SetURL(GURL(*v8::String::AsciiValue(url_value)));
     }
     return info;
   }
 
  private:
-  static bool IsLazyBackgroundPage(content::RenderView* render_view,
-                                   const Extension* extension) {
+  static bool IsLazyBackgroundPage(const Extension* extension) {
+    content::RenderView* render_view = GetCurrentRenderView();
     if (!render_view)
       return false;
+
     ExtensionHelper* helper = ExtensionHelper::Get(render_view);
     return (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
             helper->view_type() == chrome::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
   }
 
   static scoped_ptr<EventMatcher> ParseEventMatcher(
       base::DictionaryValue* filter_dict) {
     return scoped_ptr<EventMatcher>(new EventMatcher(
         scoped_ptr<base::DictionaryValue>(filter_dict->DeepCopy())));
   }
 };
 
 }  // namespace
 
 // static
-ChromeV8Extension* EventBindings::Create(Dispatcher* dispatcher,
-                                         v8::Handle<v8::Context> context) {
-  return new ExtensionImpl(dispatcher, context);
+ChromeV8Extension* EventBindings::Get(Dispatcher* dispatcher) {
+  return new ExtensionImpl(dispatcher);
 }
 
 }  // namespace extensions